A new University of Georgia study has proved for the first time that smaller dogs live longer than larger ones. The research has also determined the main cause of death for each dog breed.

University of Georgia Genetics Professor Daniel Promislow was inspired by an intriguing photo of a Great Dane and a Chihuahua walking together.

When he wondered how he could study longevity in dogs, a colleague plugged him in to a database at the National Cancer Institute.

“And the next thing I knew, I had hundreds of thousands of records of dogs, all of which had died in a veterinary teaching hospital in a university. Their ages were known, their breed was known and what they died of was described.”

Enter Katee Creevy and Jamie Fleming of the university’s College of Veterinary Medicine and Teaching Hospital, whose canine patients contributed to the data. The researchers sifted through 20 years of information on 82 different breeds of dogs. For the first time, the massive size of the database helped the scientists establish the causes of death for many uncommon breeds. Creevy introduces me to a medium size, white and brown dog who is nervously shaking in his hospital crate.

“So this is a wire-haired fox terrier. The fox terrier in general was found to have a higher risk of cardiovascular disease. An individual practicing veterinarian may simply not see enough of them in a career to have an opinion about their risk of cardiovascular disease one way or the other."

According to Creevy, better health care should result from this finding.
She now plans to start screening all fox terriers for heart problems at middle age. Creevy moves on to a black dog who is lounging more comfortably on the floor of his run, but still suspicious of visitors.

“So this is obviously a Great Dane, a very recognizable dog and at the extreme of size in the dog world. So larger dogs were prone to cancer, also musculo-skeletal diseases and gastrointestinal diseases. Good-looking one too. You’re pretty!"

On the other hand, the study shows that smaller breeds are more susceptible to metabolic diseases and toy breeds succumb to trauma. Younger dogs often die from infectious diseases.

Daniel Promislow believes the results of the study can have far-reaching implications for human health when combined with further scientific research.

“If, for example, we find a particular gene that’s associated with a disease in dogs, we can then look at that disease in humans and we have a candidate gene that we can query to ask whether that gene is also associated with that disease in humans.”

It’s not such a far-fetched notion. Dogs make even better research subjects for human health issues than other primates because there are so many of them and their physiology is very similar to humans. Katee Creevy:

“So for example, the bone marrow transplant techniques used in people were developed in dogs. The cancer chemo-therapeutics used in dogs have primarily been developed in people. So cross talk between the human medical and the veterinary medical research communities and practicing communities has long existed.”

Creevy and Promislow plan to continue their work in order to find new methods of early diagnosis and treatment, which should improve the health and quality of life for both dogs, and their humans.